Trouble Connecting and/or Using

Okay, I'm fairly new to this stuff, but my wife has a Compaq Mini that uses the Ubuntu 10.04 LTS operating system. It is connect via wifi to a Linksys E900 router. It says it is connected, but Firefox 15.0.1 (Mozilla Firefox for ubuntu canonical - 1.0) can't access the net, saying server not found. I have it set to "Auto-detect proxy settings for this network", though I've tried the no proxy setting as well. The network proxy preferences are set to direct internet connection (under system > preferences > network proxy) and the network setting for the connection as in Ad-hoc mode, using a WEP 128-bit passphrase for security. I thought I made a stupid mistake in the above settings (and still might have), but I have another wrinkle. I've tried using Update Manager, and tell it to check for updates manually. This never caused a problem before, but it "could not download all repository indexes". It says there are network problems (though it says the network connection is active 100%). It has many listed mistakes that use this format (the first of the errors):

Re: Trouble Connecting and/or Using

1. While there have been occasional problems in the past, generally it has worked fine. However, this is a new router. The router is working for all other computers in the house.
2. Rebooting the router and everything else individually was one of the first things I did and didn't help.

Re: Trouble Connecting and/or Using

Originally Posted by dugorek

Okay, I'm fairly new to this stuff, but my wife has a Compaq Mini that uses the Ubuntu 10.04 LTS operating system. It is connect via wifi to a Linksys E900 router...

Wifi always brings its own "can of worms" into the equation so, as a temporary measure, I would exclude this. Just link the computer to the router with an ethernet cable and see if you can then browse the web.

If this does work then it means that the router internet connection is configured correctly and that the problem is with either the router or the computer wifi configuration.